1. Field of the Invention
The present invention relates to a video endoscope and, more particularly, to an endoscope provided with a charge coupled device (CCD) located at the distal end of the endoscope.
2. Prior Art
Historically, whenever a patient exhibited particular symptoms which would lead a medical practitioner to believe that these symptoms would indicate a potential problem within the patient's body, an invasive procedure had to be conducted to determine whether such a problem existed and, perhaps, to rectify this problem. These procedures necessitated that a surgeon perform major surgery in the region of interest. This surgery required a relatively long period of recuperation, generally in a hospital. The expense of these procedures, as well as the required recuperation period, were both very costly.
Recently, many devices have been developed, such as endoscopes, which would allow a surgeon or other medical practitioner to view the interior of a patient's body in a much less invasive manner. U.S. Pat. No. 3,456,641 issued to Yokota et al; U.S. Pat. No. 4,253,447 issued to Moore et al; U.S. Pat. No. 4,618,884 issued to Nagasaki; U.S. Pat. No. 4,895,138 issued to Yabe; U.S. Pat. 4,918,521 issued to Yabe et al; U.S. Pat. 4,773,396 issued to Okazaki; U.S. Pat. No. 5,016,975 issued to Sasaki et al and U.S. Pat. 5,188,094 issued to Adair are typical of these types of endoscopes.
As shown in the Yokota et al patent, a camera was provided at the distal end of the endoscope to produce a signal corresponding to the features which are in the field of view of the endoscope. Subsequently, CCD's were substituted for the camera shown in the Yokota et al patent as shown in the Okazaki and Adair patents. However, since these CCD's produced a black and white image, various methods were developed to convert these black and white images to color images. A typical system of this type is shown in the Moore et al patent in which the black and white images produced by the CCD are converted into color images downstream from the distal end of the endoscope. Unfortunately, these types of systems were quite costly, since additional processing circuitry, as well as a relatively complicated lens system, would be required.